Japanese Patent Application Publication 2001-347953 discloses a steering device for vehicle having an inner column and an outer column. The inner column rotatably supports one end of a steering shaft, and the outer column rotatably supports the other end of the steering shaft and slidably fits the inner column thereinto.
In conventional steering devices as disclosed in Japanese Patent Application Publication 2001-347953, a cylindrical outer column is formed by casting. In case of casting the cylindrical outer column, a draft to pull a core out is required on an inner circumferential surface of the outer column. Furthermore, considering the telescopic adjustment and the stroke in collision, it is preferable that a part where the inner column and the outer column fit each other is cylindrical to secure a constant clearance therebetween.
Accordingly, in the casted outer column, the draft of the inner circumferential surface is cut by machining after casting so that at least the inner circumferential surface of a part where the inner column is fit has an internal diameter constantly changing along the axial direction.